Ceramic disk faucet

ABSTRACT

This covers a control valve for a kitchen or like faucet embodying a cartridge or container housing two contiguous ceramic disk elements and a vertical rotary stem. One of the elements is positioned at the base of the stem and is a rotatable member while the other element is a stationary member upon which the rotatable member is slid. The stationary member has inlet and outlet ports both so arranged that, when the movable member is rotated about its axis through a limited angle, the movable member is rotated about its axis through a limited angle, the movable member will be rotatably slid over both ports of the stationary ceramic member to determine the relative sizes of the openings of both ports. Either hot water or cold water, whichever is fed to the inlet port, may be transmitted through the valve and the angular position of the movable member will alone control the volume of water flow through the valve. The slidable member includes a cavity having a plurality of steps or ridges positioned in the path of the water reaching the slidable member, and they reduce the noise level that would otherwise be developed upon water flow through the valve. The entire flow path within the valve is essentially free of parts which expand or contract to vary the flow as the water temperature changes. Each angular valve setting will correspond to a particular flow rate which may be changed as desired but will remain independent of changes in the water temperature.

United States Patent 1191 Parkinson 14 1 May 14,1974

[ CERAMIC DISK FAUCET [75] Inventor: Richard Grant Parkinson,

Some'rville, NJ.

[73] Assignee: American Standard Inc., New York,

[22] Filed: Apr. 17, 1972 [21] Appl. No.: 244,503

[52] US. Cl. 251/304 [51] Int. Cl. F16k 31/60 [58] Field of Search137/625.17, 359; 251/304,

Primary ExaminerHenry T. Klinksiek Attorney, Agent, or Firm.leffersonEhrlich; Robert G. Crooks [57] ABSTRACT This covers a control valve fora kitchen or like faucet embodying a cartridge or container housing twocontiguous ceramic disk elements and a vertical rotary stem. One of theelements is positioned at the base of the stem and is a rotatable memberwhile the other element is a stationary member upon which the rotatablemember is slid. The stationary member has inlet and outlet ports both soarranged that, when the movable member is rotated about its axis througha limited angle, the movable member is rotated about its axis through alimited angle, the movable member will be rotatably slid over both portsof the stationary ceramic member to determine the relative sizes of theopenings of both ports. Either hot water or cold water, whichever is fedto the inlet port, may be transmitted through the valve and the angularposition of the movable member will alone control the volume of waterflow through the valve. The slidable member includes a cavity having aplurality of steps or ridges positioned in the path of the waterreaching the slidable member, and they reduce the noise level that wouldotherwise be developed upon water flow through the valve. The entireflow path within the valve is essentially free of parts which expand orcontract to vary the flow as the water temperature changes. Each angularvalve setting will correspond to a particular flow rate which may bechanged as desired but will remain independent of changes in the watertemperature 17 Claims, 10 Drawing Figures PATENIEDIH 14 97 3 8 l 0.6 ()2sum u 0F 5 FiG.8

PAIENTEIIIIIY I4 1914 3.810.602

SHEET 5 III 5 25 L11 o 2 2 I u. o 6- 3 Lu 5-- v 4 g FIG.9- 8

IL] g CERAMIC DISC FAU C E T o z I 20 4O 6O 80 I00 I20 SUPPLY PRESSUREIN P.S.l.

FLOW RATE IN GALLONS PER MINUTE |o 20 50 40 50 DEGREES ROTATION FROM OFFPOSITION CERAMIC DISK F AUCET This application relates to control valvessuch as may be used in faucets providing hot and cold water to variousplumbing fixtures, such as shower stalls or kitchen sinks or lavatories.The present invention is directed to an improved control valve that issuperior in performance characteristics, ease of operation, ease ofmaintenance, and life span when compared to a conventional or so-calledcompression type of valve quite commonly and generally used for decadesin faucets for plumbing fixtures.

This application discloses apparatus which is especially appropriate foruse in a plumbing fixture employing a faucet coupled to two separatevalves, each having a lever to control the hot and cold water,respectively, or a mixture thereof, supplied to the faucet of theplumbing fixture. In my Pat. Nos. 3,433,264 and 3,533,436, issued onMar. 18, 1969 and Oct. 13, 1970, respectively, there are disclosed valvestructures with ceramic discs which are actuated by a single lever thatis tiltable and rotatable to simultaneously control the flow and mixtureof hot and cold water emitting from the faucet. Faucets manufacturedunder or conforming to these cited patents have gained good acceptancefor their convenience, trouble-free operation, and reliability. However,there are many users who prefer to keep the convention of having twoindependent control levers, rather than a single control lever, so thatthey may separately and independently control the hot and cold watersupplies, and such users would also like to have the high performanceand reliability and smoothness of operation of a valve structure, suchas disclosed in the above-mentioned patents, which employ ceramic disks.The valve structure to be disclosed in this appli-. cation fills thatneed and at the same time embodies additional features an qualities, aswill be briefly explained hereinafter.

BACKGROUND OF THE INVENTION In the conventional faucet for a plumbingfixture, or in a shower head, there is ahandle on the left forcontrolling the flow of hot water and a separate handle on the right forcontrolling the flow of cold water. When both'handles are manipulated,whether independently or simultaneously, the desired temperature of theexit ing water delivered from the spout or shower head can becontrolled, although often with great difficulty. In the conventionalfaucet, each control valve is composed of a handle-controlled rotarystem at one end of which a rubber-like or flexible substantially flatcircular element, commonly called a seat washer, is affixed by means ofa screw serving to hold the rubber-like (elastomer) seat washer elementat the end of the stem. The control valve is equipped with a valve seatpositioned upon and concentric with the input water port, the.

valve seat being stationary and positioned opposite the verticallymovable rubber-like seat washer element. In the conventional faucet, byrotation of the stem, the rubber-like element may be moved verticallytoward or away from the valve seat to close or open the water input portas may be desired. When the valve is to be closed, the handle-controlledstem is therefore rotated in one direction so as to advance therubber-like seat washer element along its axis toward and against thevalve seat which is usually positioned at the top of the input waterport to seal the valve seat and its input Water port to cause the flowof water to be stopped. On the other hand, when the stem isrotated inthe opposite direction, the rubber-like seat washer element becomesdisplaced from the valve seat along the very same axis so as to open theinput water port and allow water to flow through the control valve to anoutput port. This type of mechanism, in which the rubber-like seatwasher element is changed in itsparallel spacing from the valve seatand'from the input water port, is widely used in control valves tocontrol the flow rate of the water through faucets which are parts ofplumbing fixtures, such as sinks or lavatories.

There are many limitations and defects in the conventional control valveof the type just referred to. For example, the elastomer seat washer issubjected to considerable abrasive wear and this it due principally tothe amount of mechanical pressure thatis usually applied to theelastomer in closing and opening the valve. As the valve is closed, theelastomerseat washer, which is attached to the stem, is rotated with atwisting motion so as to drive the seat washer against the valve seat inattaining a good shut-off of the valve. This highly abrasive rotary orshearing motion causes wear both to the elastomer seat washer and tothe'surfaceof the valve seat which is usually metallic. In due course,the elastomer seat washer becomes worn down orcut away to render itssurface uneven so that a good clean valve closure of the washer againstthe metallic valve seat may not be achievable. This usually results indifficulty in closing the valve and thedifficulty necessarily increaseswith time. Greater mechanical pressure on the handle is then required toopenand closethe valve. Abrasion and wear are further magnified inlocalities where the water supply pressure is high because, in suchareas, still greater forces are required to open or close the valve.This erosion also often results in'le'akage and wastage of water throughthe'control valve dueto'the ridges and nicks developed in the washer andperhaps also in the valve seat.Because of this known inherent weaknessof the control valve, too much'pressure is customarily applied to'thehandle of the control valve to fully close the valve to prevent leakageand wastage of water. Users of the faucet, because of their pastexperiences with leaky faucets, tend to be heavyhanded and usually shutoff the faucet with "a manual force many times greater'than is requiredand this further expands the wear and abrasion on the rubber seat washerand of the metallic valve seat. Experience abundantly reveals that, inthe absence of sufficient closing pressure, the valve will indeed'leakand'waste'water needlessly. The usual high manual pressure formechanically closing the valve is ordinarily considered imperative toprevent the constant leakage and loss of water. It is because of thisabnormal manual pressure customarily required to open and close theconventionalvalve that many people, especially childrenand old'an infirmpeople, find it difficult, and sometimes impossi ble, to open the valvewhen they desire to start the flow of water and find it equallydifficult to close the'valve when water is no longer required; Thisconstitutes a serious and long-standing difficulty with conventionalwater control valves for conventional plumbing fixtures.

Moreover, the rubber washerand the valve seat of the conventionalcontrol valve areoften subjected toa number of environmental conditionsthat additionally shorten their lives. Commonly, sand or other foreignparticles are found in the water system and, when caught between therubber washer and the seat, often become embedded in the rubber washerand scratch the valve seat as the faucet valve is closed. Whena scratchor nick is made in the valve seat, more force is naturally required bythe user to fully close the valve to eliminate leakage and a shortenedlife of the valve is inevitable. If a faucet having this type of valvestructure is allowed to drip for a length of time, the pressur izedwater under relatively higher velocity in passing through a small nickin the valve seat will erode the seat in due course, causing the scratchor nick to enlarge. This causes a larger leak, quite naturally, and acorrespondingly higher manual force on the handle will be required toavoid a dripping faucet when it is turned off. This is commonly known aswire-drawing of the seat. The sight of the leaky faucet is not uncommonin many places.

Besides the environmental problems of abrasive particlesin a watersupply, water in many areas contains chemical substances which.corrodethe common brass or bronze valve seat. Such corrosion shortens the lifeof the valve seat, whereupon the valve may have to be replaced in aperiod of time, perhaps six months.

Repairing a leaky valve in a conventional faucet is not an easy task fora homeowner and, at times, it is difficult or impossible even for amaster plumber. After a conventional faucet is in service for some time,corrosion and liming combine to seize or lock the threads on variousfaucet parts. Difficulty can be encountered in removal of gland nuts,lock nuts, and screws holding the seat washers to the stems. Removal ofthe valve seat is usually not even attempted by the homeowner and, attimes, this is found impossible even by the master plumber. Replacementof the entire faucet is costly, especially a bathtub faucet where partof a tile wall must sometimes be removed to install a new faucet.Furthermore, in the conventional compression type of valve produced fora shower head, the temperature-sensitive elastomer washer element willhave a minimal dimens'ion when the valve is closed or when cold water isreceived, but the element will expand when it is subjected to theelevated temperature of hot water. Hence, the

size of the opening of the valve having such an expandible andcontractable element in the control path will vary, depending upon thetemperature of the incoming water. As the temperature rises and theelastomer element necessarily expands, the size of the water openingwill be correspondingly reduced and soon reduce the amount of warm orhot water delivered through the valve. This can be especiallyuncomfortable in a shower stall because the temperature of the waterwill change even though the user intends to maintain the temperaturesubstantially constant and therefore has not readjusted the valve. Thisconstitutes another important deficiency in the common conventionalcompression type of valve and points up an added reason for effectivelyremoving elastomer elements from essential flow paths or otherwiseminimizing the difficulties that may be developed by their presence.

Other structural features of a conventional faucet also contribute tothe difficulty in achieving the proper adjustment of the valve by theuser to get the desired flow rate and the desired temperature of thewater. For example, the normal looseness of the meshing stem threadscauses variations in the valve opening, the magnitude of the variationsusually depending upon whether the handle of the valve is being adjustedtoward its open position or toward its closed position. As the threadswear with use, this condition becomes more acute.

Many, if not all, of the above-noted difficulties have been plainlyobvious throughout the decades, but very little has been done to remedyand obviate the difficulties which are ever present even in newlyconstructed homes.

SUMMARY OF THE INVENTION Accordingly, a control valve has been achievedaccording to this invention which is virtually free of many, if not all,of the infirmities and difficulties of prior conventional mechanisms forplumbing fittings. The valve of this invention may be usedinterchangeably for either hot water or cold water, whether for kitchensor bathrooms. The present invention is, therefore, directed to a highlyimproved, simplified, longlived, and relatively silent control valvewhich may be opened repeatedly or intermittently through a predeterminedangle to establish a corresponding predetermined volume flow rate, andopened through another predetermined angle to obtain anothercorresponding predetermined volume flow rate, and closed, wheneverdesired, to completely shutoff the flow of water. All of theseimprovements in the opening and closing of the valve of this inventionmay be accomplished with ease and without the employment of excessivemanual or mechanical pressure and without damage to or destruction ofany of the movable and stationary elements. This valve structures meetsa long felt want, especially because it virtually eliminates the seriousdifficulties encountered in conventional water control valve forconventional plumbing fixtures.

In accordance with the present invention, the control valve includes apair of hard contacting ceramic members, one of which is alwaysstationary and entirely free of any motion, while the other member iscontrolled by arotary stem which never moves axially, so that the otherelement is always in slidable contact with the stationary element tocontrol the volume flow rate of the water. When the handle-controlledstem of the control valve is rotated for opening the valve, the slidableceramic element will he slid along the surface of thestationary ceramicelement and the slidable element may be moved over an angle whichcorresponds to the angle of rotation of the stem to achieve apredetermined opening of the valve port without changing the spacing orcontinuous contact between both ceramic elements. If the stem is rotateda bit further in the same direction, the valve port will be furtheropened by a proportional increment. On the other hand, when the stem isrotated .in the opposite direction, the valve port will be substantiallyreduced in size to reduce the volume flow rate of water. When the stemis rotated further in the opposite direction through a sufficient angle,the valve port will be closed and there will be no further flow of waterthrough the valve.

Thus, a rotational movement of the handlecontrolled stem of the valvefrom its initial open position or its initial closed position willcause, for each individual angular rotation of the stem, a predeterminedand corresponding change in the opening of the port of the valve. Theproportionality of the changes in the flow rates will remainsubstantially the same in both directions of change. The mechanism willbe substantially free of wear and erosion for many years. Furthermore,the movement of the slidable ceramic disk in response to each rotationaldisplacement of the stem of the valve can be achieved with the samerelatively small torsional force applied to the stem and will notrequire the unusual and uneven torsional forces usually required inconventional valves to control such valves when they are to be opened orclosed.

The two ceramic disks employed in and characteristic of this inventionare enclosed in a common casing or cartridge and are expected to be usedtogether for a very long time, perhaps twenty years, without requiringany re-adjustment or any maintenance service or any replacement of anyof the parts. On the other hand, should a replacement or repair becomenecessary, the entire valve structure may be perfected merely byreplacing the cartridge. This may be done by almost any unskilledperson, so that the need for a plumber to make the valve replacement orrepair will be unnecessary.

This invention, together with its objects and features, will be betterand more clearly understood from the following more detailed descriptionand explanation hereinafter following when read in connection with theaccompanying drawing in which:

FIG. 1 illustrates an exploded view of the structure of the cartridge ofthe control valve mechanism of this invention;

FIG. 2 shows a perspective view of the structure of the generalarrangement of this invention, this figure showing also an exploded viewof the left end portion of the faucet;

FIG. 3 illustrates a front elevational view of the general arrangementof this invention, this figure also illustrating, in cross-section, partof the control valve structure;

FIGS. 4, 5, 6 and 7 illustrate schematically four different views of thetwo ceramic disk members corresponding to different angular positions ofthe movable ceramic disk member;

FIG. 8 shows a cross-sectional view of the two ceramic disk memberstaken along the line AA of FIG.

FIG. 9 illustrates two curves generally representing the respectiveforces required to manipulate the handle of a conventional faucet valvesubjected to different pressures of the incoming water, and the handleof a faucet of the kind involved in the present invention and subjectedto similar forces; and

FIG. 10 illustrates two curves comparing the flow rates of theconventional valve with the valve of this invention for differentangular rotations of the handles of the respective faucet valves.

The same or similar reference characters will be employed throughout thedrawing to designate the same or similar parts wherever they may occurin the drawing.

Referring generally to the drawing and especially to FIGS. 1 and 2 ofthe drawing which illustrate exploded representations of the controlvalve mechanism of this invention, and referring also to FIG. 3, thereference character CTG designates a cartridge which houses the twosubstantially parallel contiguous ceramic disks or elements D81 and D82employed in this invention. The upper ceramic disk D51 is rotatableabout its center or axis and, in its rotation, is always slidable alongthe upper surface of the lower ceramic disk DS2 which is and remainsalways stationary and immovable and is always held stationary andimmovable. The upper disk D81 is mounted within and held by projectionsSP1 and SP2 which are part of and integral with the structure of stem STso that the upper disk DS! is rotatable and slidable about its centralor vertical axis. When the stem ST is rotated through any angulardisplacement for efiecting a change in the flow rate through the controlvalve, the stem ST will necessarily rotate both the upper disk DS] andthe stem projections SP1 and SP2 which retain the upper disk SDI,through an equal and corresponding angular distance without causing thelower disk DS2 to be rotated or otherwise moved or changed in itsposition. Inasmuch as a sliding motion alone is involved between the twodisks, the spacing between the two disks D51 and D82 will neverthelessremain unchanged throughout the sliding motion. The two disks D81 andD52 will be maintained in constant contact with each other although theupper disk DSl may be rotated and slid into different angularconfigurations by various and different rotations of stem ST. The stemST and disks D81 and D82 may be considered to have a common axis, butonly the stem ST and the upper disk DSl are revolvable, and they arerevolvable as a unit through the same angle about the common axis by anyrotation of the stem ST.

The lower disk D82 is held fixed and immovable, both rotationally andaxially or laterally, within the cartridge body BD by the rather wideprojections PJ] and PJ2 of disk DS2, the latter projections being heldbetween the pairs of guiding projections GPl and GP2 (see FIG. 1) on theinner wall of the cartridge body BD, as will be later explained. Thelower disk D82 is retained against downward displacement or movement bya cap CP which has two substantially equal openings CO1 and CO2 forwater inflow and outflow, respectively. These openings CO1 and CO2 incap CP are aligned with two corresponding counterbores CB1 and D02 inthe lower or stationary disk DS2 (see FIG. 1). The cap CP also embracesand supports two equal cylindrical seal rings SR1 and SR2 which may bemade of any forms of elastomer or rubber-like materials and, as may beseen in FIGS. 1 and 3, they are sufficiently long so as to enter into,and be retained by, the two respective counterbores in the lower ceramicdisk D52.

The cap CP is positioned above the base nut BN which may be positionedimmediately beneath the support SB which may be, for example, theplatform of a kitchen sink, as shown in FIG. 2 An escutcheon ES servesas a trimming mounted above and about the base nut BN, as shown, theescutcheon ES also having aesthetic value.

A water inlet passageway IT and a water outlet passageway OT may bealigned with each other somewhat as illustrated in FIG. 3. Thesepassageways IT and OT have neck portions TN] and TN2. Water enteringinlet tube or passageway IT will travel upward through the valvemechanism to the cavity in the upper disk DSl, then return via a downpath in the valvemechanism, and then traverse the outlettube' orpassageway OT to be exited by the faucet spout PT. The upper disk DSlsignificantly has a fluid cavity but no fluid aperture or throughpassage.

It will be observed that each of the cylindrical seal rings SR1 and SR2has a diameter which is appreciably greater than the opening of each ofthe neck portions TNl and TN2 of passageways IT and OT, respectively.

7 Moreover, the rings SR1 and SR2 are longer than the overall verticallengths of the two corresponding openings CO1 and CO2 ofithe' CP and therespectivecounterbores CB1 and CB2 of lower disk DS2, as may beapparentfrom FIG. Because of this significant geometry of the indicatedcomponents, any expected changes in the sizes of the elastomer rings SR1and SR2 due to even wide temperature changes will not expand rings SR1and SR2 so as to reduce or otherwise affect the rate of flow of waterthrough either of the passageways IT or OT. Thus, the flow of water willbe maintained rathercompletely independent of changes of the size of theelastomer rings SR1 and SR2 over any very wide temperature range thatmay be encountered in every day use of the valve mechanisms.

The base nut BN has an internally threaded section BTH above which maybe applied a flat washer WSl.

I threads of the inlet supply shank 158. The shank 188 will be coupledto the inlet water supply pipe SP as shown (see FIG. 3). The base nut BNmay be rotated about the externally threaded segment of the shank 158 soas to apply pressure between the base nut RN and the support SB throughthe washer WSl to hold the base nut BN in a permanently stationaryposition and thereby hold the faucet against upward movement.

As shown in FIG. 2, a handle I'IN is mounted upon the stem ST and isaffixed to the stem ST .by a simple screw SC which is threaded into theupper serrated end of the stem ST. The opening within the handle l-INwill be brought down almost to the upper surface of escutcheon ES, asseen at the right of FIG. 3.

By rotating the handle I-[N in one direction or the other, the stem STwill be rotated through a corresponding angle to slidably rotate theupper disk DSl on and about the upper surface of the lower disk DS2without changing the spacing, and without affecting the intimatecontact, between the disks D51 and DS2. In other words, the ceramicdisks DS] and D82 remain in firm contact with each other and the upperdisk DSl remains inslidable contact with the lower disk D82 even thoughthe upper disk D81 is rotated to enlarge or reduce the. effective. sizesof the portal openings within the lower or stationary disk D52, as maybe desired, through which water may enter via the inlet IT and exitthrough the outlet OT to the faucet spout Fl. In still other words, therotation of the handle I-IN simply produces a rotational movement of thestern ST without changing the longitudinal position of the handle RN andwithout translatory movement of the stem ST and without changing thelongitudinal position of the movable upper disk DSl with respect to thestationary disk D52. There is, therefore, no longitudinal movement ofany of the parts of the cartridge CTG at any time, even while the volumeflow rate of water is changed from time to time as desired by the user.A further feature is the continuous upward pressure exerted by theincoming water against the inner wall of the lower stationary disk DS2acting to firmly hold the lower disk DS2 sealed against the upper diskDSl while allowing the disk DS2 to be held stationary and allowing theupper disk DSl to berotated and slid, as often as desired, over thesurface of the lower disk DS2 by rotation of the handle HN and of thestem ST by the user.

A washer W82 (see FIG. 1) is mounted about stem ST above the shouldersor projections SP1 and SP2 of the stem ST and within the inner wall-ofthe body BD of the cartridge CTG. This washer W52 is preferably made ofTeflon or a like material which will have a sufficiently lowcoefficient'of friction so as not to retard or otherwise interfere withthe rotary action of the stem ST when the handle HN is manipulated tochange the flow rate. The washer WS2 serves as a thrust washer toprevent the upward movement of the stem ST in re sponse to the pressureof the water received through the water inlet IT as the water travelsthrough the two apertures of the lower disk D82 and through the steppedcavity of the upper disk DSl to be emitted by outlet OT (see FIG. 2).

As already explained, FIG. 1 shows the exploded view of the componentsof the cartridge CTG with the handle HN of the valve removed. The tworetaining screws RS serve to maintain the cartridge CTG affixed to thefaucet pad FP (see FIG. 2) in which there are two internally threadedopenings to receive the screws RS. The threaded openings in pad FP serveto grip and hold the ends of screws RS.

FIG. 2 shows the relative positions of the retaining screws RS withrespect to the cartridge CTG. When it is desired to remove the cartridgeCTG, it is only necessary to remove the screw SC from the stem ST(within the handle HN) and then remove the two retaining screws RS,whereupon the cartridge CTG may be easily and quickly removed andreplaced by another cartridge if this should be desired.

When the platform or support SB of a fixture, such as a sink, is to havethe control valve installed, this can be easily accomplished merely byapplying the washer WS] and the base nut BN on one side of the supportSB and joining the base nut to the external threads of the inlet supplyshank 158. The water supply pipe SP may then be coupled to the inletsupply shank [88 by means of a retaining or coupling nut CN, as shown inFIG. 3.

FIGS. 4, 5, 6 and 7 are views looking at the underside of the cartridgeCTG, with the cap CP and the seal rings SR1 and SR2 removed. These viewsshow the various, openings of the inlet port D01 and outlet port D02 asthe stem ST may be rotated to certain angular positions.

FIG. 4 shows the valve in its closed position, with wings SP1 and SP2that project from shoulder SS on stem ST abutting projections GPl andGP2 of body DB. It is noted that there is an appreciable distancebetween the edge of the inlet port D01 of lower disk D82 and the edge ofthe stepped cavity STP in upper disk D8! which has no aperture orthrough passage for fluid transmission. Because the inlet port D01 ofthe lower disk D52 is spaced from the stepped cavity STP, no water canflow through the outlet port D02.

FIG. 5 shows the shape of the port openings when the handle ispositioned to provide a very low rate of flow through the faucet FT. Theintersection of inlet port D01 in the lower disk D52 and the steppedcavity STP in the upper disk DSI form a geometric shape that increasesslowly and gradually during the first few degrees of opening effected bya small rotation of stem ST near the off-position. This provides finetuning when low flow rates are desired; This also inhibits water hammerwhen the stem ST is returned to its closed position even when the handleI-IN is closed quickly.

FIG. 6 shows the port openings when the valve is placed in a half-openposition. The inlet port D01 in the lower disk D82 is approximately 50percent open and the outlet port D02 in the lower disk D52 isapproximately 60 percent open. This throttling of the outlet port D02 inrelationship to the throttling of the inlet port D01 in all partiallyopen positions of the valve induces a back pressure in the steppedcavity STP in the upper disk DSl. This back pressure inhibits cavitationby reducing the number and size of cavitation bubbles that form as thewater at high velocity passes through the inlet port D01 into the cavitySTP.

FIG. 7 depicts the valve in its fully open position. Note that both theinlet port D01 and the outlet port D02 are completely open to thestepped cavity STP and that the water cannot now be throttled at eitherport. Therefore, it can be seen that, because the outlet port D02 isopened in conjunction with the inlet port DOl, this will not reduce theflow rate of the water in the fully open position of the cartridge CTG.

FIGS. 1 and 8 show the general contour of the steps in the non-aperturedcavity STP of the upper ceramic disk DSl. The steps are five in numberfor illustration. The cavity STP within disk D81 is bounded by theseveral steps therein and is part of the fluidic interconnection pathfor water received from the inlet conduit IT and transmitted through theoutlet conduit OT. The sizes of the openings made available for waterflowing into and out of the stepped region STP will be determined onlyby the angular displacement of the upper ceramic disk DSl. The spacewithin the stepped cavity STP may be completely cut off from the inletconduit IT merely by rotating the stern ST to one of its two extremepositions (see FIG. 4). n the other hand, coupling space within cavitySTP will be brought to its greatest size when the stem ST is rotatedabout its axis to its other or opposite extreme position (FIG. 7).

The cavity embodying the five steps in the stepped region STP serves toprovide a conduit between the inlet passageway IP and the outletpassageway 0P (see FIG. 2) and the steps in the cavity also provideridges for the substantial reduction or elimination of noise. It is awell known fact that cavitation will occur when the velocity of a liquidis raised sufficiently high so as to cause the pressure to drop to avery low level a level approximating the vapor pressure of the liquid.Any substantial decrease in pressure often causes air bubbles to beformed and the bubbles grow in size until they reach a fluid zone ofhigher pressure. The developed higher pressure may be sufficient toburst the bubbles. The sudden collapse of the bubbles generates anundesirable but quite distinct audible noise. The edges of the ridgesproject into the fluid stream carrying the bubbles and act to divide ordistribute the bubbles. The sharp ridges within cavity STP may cause thebubbles to be reduced in size or broken up. Hence, those bubbles thatare not broken up are neverthesless prevented from growing large enoughto cause excessive noise.

FIG. 8 shows an enlarged cross-sectional view of the two disks D81 andD82, especially magnifying the ridged region of the upper ceramic diskDSl. Each ridge may be regarded as having two semi-circular segments(see FIG. 7). Each segment includes parts of the several ridges and theyhave a common center as shown. Other parts of the ridges have a likecommon center. The line joining the two centers of the ridged section ispitched at an angle, such as 21, with respect the normal vertical lineas shown in FIG. 4. The two inner circular openings D01 and D02 of thelower disk DS2 provide the through paths for water flow. Water enteringopening D01 reaches the ridged cavity arena STP of the upper disk DSl,then turns around within the cavity of the upper disk D81 and returnsthrough opening D02.

Two valves may be arranged on a sink or lavatory organized so that oneof the inlet shanks ISl may receive hot water and the other inlet shank(not shown) may receive cold water. The two outlet passageways 0? may beconnected by conduit OT to the faucet spout FT, as shown in FIG. 2, toreceive and discharge both outputs as water of an intermediatetemperature. The intermediate temperature will, of course, be fixed bythe adjustments of the handles of the two valves.

While each control valve has been shown and described as having a leverhandle HN to control the movement of its stem ST, the handle may be acircular handle or any other means for rotating the associated stem ST.

FIG. 9 presents a chart that shows the torques needed to operate thehandle HN of the valve of the disclosed invention as compared to thatneeded to operate the handle of a conventional compression-type faucetvalve. The torques needed to turn the handle I-IN are compared at thevarious inlet supply pressures that are commonly found in this country,the range extending from about 20 psi to about psi. The marked lesserforce required to adjust the valve of this invention will I be readilyapparent. The lesser required forces render the device of this inventionoperable by childrem as well as older or infirm people with equalfacility. This is a distinct improvement. rapidly I FIG. 10 illustratestwo curves drawn to compare a conventional valve with the valve of thisinvention as to the volume flow rate (in g.p.m.) with respect to theangular rotation of the handle l-IN of the valve from its off position.It will be readily apparent that the valve of this invention, whenopened to start its flow, transmits water at a much slower rate ofvolume growth (see the dotted curve), but that the growth rate risesmuch more radpily as the angular displacement is increased. Hence afiner control is obtained at the lower flow rates. This makes it easierfor the user to select lower flow rates.

Both FIGS. 9 and 10 exemplify the surprisingly large advantages of thevalve of this invention over conventional valve structures heretoforeemployed in plumbing fixtures.

The disks D81 and D82 are preferably made of an alumina ceramic materialbecause such material has dimensional stability and its surfaces canbeground and polished to such a degree of flatness and smoothnessthat aliquid cannot pass between the contiguous surfaces. To effect the sealbetweenthe contiguous -surfaces, a predetermined minimum contactpressure should be maintained to hold the surfaces in continu ousabutting relationship even if one :of the disks is to be slid over thesurface of the other disk. The contact pressure is achieved withoutsprings.

To effect the required seal, the seal rings SR1 and SR2 are 'made longerthan the height of the apertures CO1 and C02 within the cap CIthatsupportthe rings (see FIG. 1), so that the upper portions of ringsSR1 and SR2 protrude into the enlarged cavities CB1 and CB2,respectively, of the stationary disk DS2. Because of their lengths asalready noted, the rings SR1 and SR2 will therefore be compressed,thereby exerting'a continuous upward force against disk D82. The upwardforce will hold the two disks together.

The seal of the mating surfaces of disks D81 and D82 remains effectivecontinuously and is virtually independent of the inlet water pressure,however high or low it may be. Because of the low coefficient offriction between disks D81 and D82 and because of the presence of theTeflon washer WS2, the amount of torque required to operate the valveremains quite low even when the water pressure is relatively high.

Because of dimensional stability of the alumina ceramic disks, thehandle HN may be moved to a desired position at different times and'thevolume of water flow through the valve will remain unchanged,notwithstanding changes in temperature of the fluid or in theenvironment or in the time intervals between the suc cessive valveoperations. The valve can therefore be rapidly brought to a positioncorresponding to a desired flow rate at any time. The valve maytherefore be adjusted to a desired flow rate quickly and easily.

Because the ceramic disks D81 and D52 are harder than sand and otherforeign materials found in water systems, the surfaces of the disksremain smooth and unscratched by foreign particles and are preserved insealing, leak-proof condition for long periods of time. The intimatecontact between such flat, highly polished surfaces precludes foreignmatter from reaching the surfaces in contact with each other.

The valve cartridge CTG is self-contained and is easily replaceable bythe homeowner without encountering the difficult problems usually facingthe homeowner in repairing a conventional faucet. The faucet becomesoperative anew immediately upon the replacement of the cartridge.

The disks D81 and D82 have been described as made of alumina ceramicmaterials. Such materials are preferred for the disk devices. The diskdevices are readily made of such materials in large quantities and atrelatively low cost, and their shapes can readily conform to precisedimensions. Such materials can be highly polished to provide easilyslidable surfaces presenting minimal resistances. When so polished,leakage of water between adjacent disks becomes virtually nonexistant.However, other hard materials may be used in place of alumina ceramics.For example, metals such as stellite or tungsten carbides may be usedfor the disks, but such hard materials would be more costly tomanufacture and, moreover, they do not provide the hardness andprotection against sand particles conveyed by the water.

A Williams Pat. No. 3,009,679 issued Nov. 21, 196i discloses a valvestructure having, among other things, a valve seat of a graphitecomposition positioned on a water inlet passage, an O-ring' mountedaround the circumference of the valve seat to seal the valve seat fromthe inlet passage, a hard valve member rotatably mounted on the valveseat and affixed to a rotatable valve stem, and a spring seated on ashoulder within the inlet passage and pressuring the bottom of the valveseat against the valve member. The valve member embodies an eccentricport which may be aligned with another port in the valve seat. Byrotating the valve stem, the ports are brought into alignment orregistry or out of alignment or registry to control the flow ratethrough the valve. This structure with its O-rings, its through ports inthe adjacent valve seat and valve member, its biasing spring, etc.,constitute a complicated valve of lesser value in manufacturing,maintenance and operat-' ing features than the simple distinctivecartridge valve of the present invention.

What is claimed is:

l. A faucet valve for controlling the rate of flow of fluid between afirst conduit and a second conduit to be coupled to the valve,comprising first and second ceramic disks in contact with each other soas to have a common interface, the first disk having only two aperturesfor'the flow of fluid, means in the valve to hold said first diskagainst rotation, said two apertures extending through said disk andcoupled respectively to said first and second conduits, the second diskhaving an elongated unapertured cavity at the common interface ofsufficient length and depth so as to provide the sole coupling betweenthe two apertures, manually controlled means peripherally coupled to thesecond disk for slidably rotating the second disk about a single axisalways perpendicular to the common interface for changing the positionof its cavity with respect to both apertures and thereby adjusting thefluid flow rate, said manually controlled means including asubstantially cylindrical rotary stem mechanically retaining the seconddisk at one end of said stem, said manually controlled means includingmeans to prevent any motion other than rotary motion of the second diskand to prevent any change in the spacing between the two disks, andresilient means for applying pressure against one of the disks forcontinuously maintaining the two disks in physical contact with eachother at the interface during all changes in pressure of the incomingfluid and during all rotations of the second disk.

2. A faucet valve according to claim 1 in which the manipulation of thestem controls only the angular rotation of the second disk, the valveincluding a substantially cylindrical collar within which the stem isconfined so that the second disk is slidably rotatable solely about itsaxis.

3. A faucet valve according to claim 2 including a housing enclosing thefirst and second disks and the lower segment of the stem, the resilientmeans including cylindrical elastomer rings inserted within saidapertures of said first disk to apply pressure to the first disk tomaintain it in contact with the second disk at the interface, and a capfor supporting said elastomer rings and holding said elastomer ringsagainst the first disk.

4. A faucet valve according to claim 3 including a handle coupled totheupper segment of the stem for manually imparting rotation to thestem.

5. A valve for the control of the rate of flow of fluid through aplumbing fitting, comprising a longitudinal non-translatory stem whichis rotatable and movable only about its axis without being movable inany other direction, a rotatable solid disk affixed to the base of saidstem and rotatable through an angle corresponding to the angle ofrotation of the stem and having a longitudinal fluid coupling cavitytherein, a stationary solid disk having two parallel identical aperturestherein for for the flow of the controllable fluid therethrough, therotatable disk being slidable along the adjacent surface of thestationary disk, means for applying pressure between the two disks formaintaining the two disks in continuous slidable contact with each otherand inde-.

. aligned with said apertures upon the axial rotation of the stem, thecavity providing the coupling between the twoapertures to control theflow of fluid through and between said apertures, two conduitsrespectively coupled to the two apertures of the stationary disk, one ofthe apertures being supplied with pressurized water and the otheraperture exiting the pressurized water received from the first apertureand transmitted through the cavity of the rotatable disk, said means formaintaining the two disks in continuous slidable contact including ahousing having a collar within which the stem is guided to enable thestem to be moved only in rotation about its axis for holding therotatable disk against movement other than rotary movement, and astationary abutment means for limiting the angular rotations of the stemand the rotatable disk, said latter means comprising projections on saidstem and corresponding curvatures about the rim of the rotatable disk.

6. A valve for the control of the rate of flow of fluid through aplumbing fitting, comprising first and second I solid disks stackedtogether so as to be in continuous contact with each other, the firstdiskhaving a first aperture for the reception of fluid and a secondsubstantially equal aperture for the discharge of the received fluid, anabutment means for holding the first disk stationary, the second diskhaving a cavity but no apertures, the cavity of the second diskfluidically coupling the two apertures to each other, a rotatablelongitudinal stem the end of which has means to hold said stemperpendicular to the second disk to slidably rotate the second diskabout its axis and along the adjacent surface of the first disk and tocontrol the angle of slidable rotation of the second disk upon thesurface of the first disk, the two disks being held in contact with eachother throughout each rotation of the second disk, the valve havingmeans to hold the stern non-movable longitudinally so as to maintain thesurface contact between the two disks unchanged and to prevent anymotion of the second disk except its rotary motion, whereby the rotationof the second disk in response to the rotation of the stem will controlthe volume of fluid flow from said first aperture through said cavityand exiting through said second aperture.

7. A valve according to claim 6, in which the cavity of the second diskis formed to have a plurality of steps having ridges for reducing thenoise developed by the flow of fluid through the cavity.

8. A valve according to claim 7, including elastomer .means for applyingpressure between the two disks to maintain them in continuous contactwith each other during the rotations of the .stem and the second disk.

9. A valve according to claim 8, including a housing for enclosing andretaining the stem and the two disks in their respective positions, saidhousing providing the abutment means an abutment for holding the firstdisk continuously against any movement.

10. A valve according to claim 9 in which the disks are made of aluminaceramic material.

11. A valve according to claim 10 including a thrust washer interposedbetween the stem and the housing, said washer having a low coefficientof friction.

12. A valve for a plumbing fitting for the control of the rate of theflow of fluid through the fitting, comprising a longitudinal stem whichis rotatable about its axis but is not movable in any other directionalong its axis, a first solid disk having a first aperture for receivingfluid and a second substantially identical aperture for discharging thereceived fluid, means for holding the first disk stationary, means foradjustably coupling the apertures of the first disk to each other tocontrol the rate of flow of fluid between saidapertures, said couplingmeans including a second solid disk having a cavity therein but noaperture so that fluid may flow from said first aperture through thecavity and out of the second aperture, said second disk having at leastone pro jection which mates with a corresponding projection formed onone end of said stern so that, in response to collarwithin which thestem is rotatable to prevent any non-axial rotation of the stern and ofthe second disk.

13. A valve according to claim 12 including means supported beneath thefirst disk for continuously holding the first disk stationary, and forapplying pressure against the first disk to hold it in continuouscontact with the second disk throughout all rotations of the seconddisk.

14. valve according to claim 13 including first and second elastomercylindrical units which are larger in their external diameters than thediameters of the apertures of the first disk and are positioned betweenthe first disk and the support means so as to be coaxially within therespective first and second apertures, said cylindrical units applyingcontinuous mechanical pres-v sure between the support means and thefirst disk.

17. A faucet valve for controlling the rate of flow of fluid between afirst conduit and a second conduit to be coupled to the valve,comprising first and second ceramic disks in contact with each other soas to have a common interface, the first disk having two aperturesextending through said disk and coupled respectively tosaid first andsecond conduits, the second disk having an elongated unapertured cavityat the common interface of sufficient length and depth so as to providethe sole coupling between the two apertures, manually controlled meansperipherally coupled to the second disk for slidably rotating the seconddisk about a single axis always perpendicular to the common interfacefor adjusting the fluid flow rate without rotating the first disk andwithout changing the spacing between the two disks, resilient means forapplying pressure against one of the disks for continuously maintainingthe two disks in physical contact with each other at the interfaceduring all changes in pressure of the incoming fluid and during allrotations of the second disk, said manually controlled means includes asubstantially cylindrical rotary stem mechanically retaining the seconddisk at one end of said stem to control the angular rotation of thesecond disk and also includes a substantially cylin drical collar withinwhich the stem is confined so that,

mer means and holding said elastomer means against the first disk, and,a handle coupled to the upper seg* ment of the stem manually imparting,rotation to the stem, the base of the stem and the second disk havingprojections for limiting-the slidable rotation of the second disk andthe angular rotation of the stem and for mechanically coupling bothdisks to each other.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,810,602 Dated May 14, 1974 Inventor(s) Richard Grant Parkison It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

IN THE ABSTRACT Lines 9 and 10, delete the phrase "the movable member isrotated about its axis through a limited angle" IN THE SPECIFICATIONColumn 1, line. 37, delete "an" and insert -and-.

Column 9, line 57, delete "neverthesless" and insert -nevertheless--Column 10, line 33, delete' childrem" and insert -chi3;dren-; line 35,delete "rapidly" t Period IN THE CLAIMS Claim 5, Column 12, line 62,delete '"for".

Claim 9, Column 13, line 60, delete means for an abutment" Signed andsealed this 13th day of May 1975.

(SEAL) .1 TAtteSt: .4

v C. MARSHALL DANN RUTH C. MASON Commissioner of Patents AttestingOfficer and Trademarks :RM PO-IOSO (10-69) USCOMM-DC 60376-P69 U.5.GOVERNMENT HUNTING OFFICE "69 0-56-3154.

1. A faucet valve for controlling the rate of flow of fluid between afirst conduit and a second conduit to be coupled to the valve,comprising first and second ceramic disks in contact with each other soas to have a common interface, the first disk having only two aperturesfor the flow of fluid, means in the valve to hold said first diskagainst rotation, said two apertures extending through said disk andcoupled respectively to said first and second conduits, the second diskhaving an elongated unapertured cavity at the common interface ofsufficient length and depth so as to provide the sole coupling betweenthe two apertures, manually controlled means peripherally coupled to thesecond disk for slidably rotating the second disk about a single axisalways perpendicular to the common interface for changing the positionof its cavity with respect to both apertures and thereby adjusting thefluid flow rate, said manually controlled means including asubstantially cylindrical rotary stem mechanically retaining the seconddisk at one end of said stem, said manually controlled means includingmeans to prevent any motion other than rotary motion of the second diskand to prevent any change in the spacing between the two disks, andresilient means for applying pressure against one of the disks forcontinuously maintaining the two disks in physical contact with eachother at the interface during all changes in pressure of the incomingfluid and during all rotations of the second disk.
 2. A faucet valveaccording to claim 1 in which the manipulation of the stem controls onlythe angular rotation of the second disk, the valve including asubstantially cylindrical collar within which the stem is confined sothat the second disk is slidably rotatable solely about its axis.
 3. Afaucet valve according to claim 2 including a housing enclosing thefirst and second disks and the lower segment of the stem, the resilientmeans including cylindrical elastomer rings inserted within saidapertures of said first disk to apply pressure to the first disk tomaintain it in contact with the second disk at the interface, and a capfor supporting said elastomer rings and holding said elastomer ringsagainst the first disk.
 4. A faucet valve according to claim 3 includinga handle coupled to the upper segment of the stem for manually impartingrotation to the stem.
 5. A valve for the control of the rate of flow offluid through a plumbing fitting, comprising a longitudinalnon-translatory stem which is rotatable and movable only about its axiswithout being movable in any other direction, a rotatable solid diskaffixed to the base of said stem and rotatable through an anglecorresponding to the angle of rotation of the stem and having alongitudinal fluid coupling cavity therein, a stationary solid diskhaving two parallel identical apertures therein for for the flow of thecontrollable fluid therethrough, the rotatable disk being slidable alongthe adjacent surface of the stationary disk, means for applying pressurebetween the two disks for maintaining the two disks in continuousslidable contact with each other and independent of the fluid pressurewhenever the stem is axially rotated, the cavity of the rotatable diskbeing variably and adjustably alignable with the two apertures of thestationary disk and variably and adjustably dis-aligned with saidapertures upon the axial rotation of the stem, the cavity providing thecoupling between the two apertures to control the flow of fluid throughand between said apertures, two conduits respectively coupled to the twoapertures of the stationary disk, one of the apertures being suppliedwith pressurized water and the other aperture exiting the pressurizedwater received from the first aperture and transmitted through thecavity of the rotatable disk, said means for maintaining the two disksin continuous slidable contact including a housing having a collarwithin which the stem is guided to enable the stem to be moved only inrotation about its axis for holding the rotatable disk against movementother than rotary movement, and a stationary abutment means for limitingthe angular rotations of the stem and the rotatable disk, said lattermeans comprising projections on said stem and corresponding curvaturesabout the rim of the rotatable disk.
 6. A valve for the control of therate of flow of fluid through a plumbing fitting, comprising first andsecond solid disks stacked together so as to be in continuous contactwith each other, the first disk having a first aperture for thereception of fluid and a second substantially equal aperture for thedischarge of the received fluid, an abutment means for holding the firstdisk stationary, the second disk having a cavity but no apertures, thecavity of the second disk fluidically coupling the two apertures to eachother, a rotatable longitudinal stem the end of which has means to holdsaid stem perpendicular to the second disk to slidably rotate the seconddisk about its axis and along the adjacent surface of the first disk andto control the angle of slidable rotation of the second disk upon thesurface of the first disk, the two disks being held in contact with eachother throughout each rotation of the second disk, the valve havingmeans to hold the stem non-movable longitudinally so as to maintain thesurface contact between the two disks unchanged and to prevent anymotion of the second disk except its rotary motion, whereby the rotationof the second disk in response to the rotation of the stem will controlthe volume of fluid flow from said first aperture through said cavityand exiting through said second aperture.
 7. A valve according to claim6, in which the cavity of the second disk is formed to have a pluralityof steps having ridges for reducing the noise developed by the flow offluid through the cavity.
 8. A valve according to claim 7, includingelastomer means for applying pressure between the two disks to maintainthem in continuous contact with each other during the rotations of thestem and the second disk.
 9. A valve according to claim 8, including ahousing for enclosing and retaining the stem and the two disks in theirrespective positions, said housing providing the abutment means anabutment for holding the first disk continuously against any movement.10. A valve according to claim 9 in which the disks are made of aluminaceramic material.
 11. A valve according to claim 10 including a thrustwasher interposed between the stem and the housing, said washer having alow coefficient of friction.
 12. A valve for a plumbing fitting for thecontrol of the rate of the flow of fluid through the fitting, comprisinga longitudinal stem which is rotatable about its axis but is not movablein any other direction along its axis, a first solid disk having a firstaperture for receiving fluid and a second substantially identicalaperture for discharging the received fluid, means for holding the firstdisk stationary, means for adjustably coupling the apertures of thefirst disk to each other to control the rate of flow of fluid betweensaid apertures, said coupling means including a second solid disk havinga cavity therein but no aperture so that fluid may flow from said firstaperture through the cavity and out of the second aperture, said seconddisk having at least one projection which mates with a correspondingprojection formed on one end of said stem so that, in response to anyrotation of said stem about its axis, said second disk will slidablyrotate about an axis and along the surface of the first disk to changethe position of said cavity between the apertures of the first disk tocontrol the fluid flow rate through the valve, and a stationarycylindrical collar within which the stem is rotatable to prevent anynon-axial rotation of the stem and of the second disk.
 13. A valveaccording to claim 12 including means supported beneath the first diskfor continuously holding the first disk stationary, and for applyingpressure against the first disk to hold it in continuous contact withthe second disk throughout all rotations of the second disk.
 14. A valveaccording to claim 13 including first and second elastomer cylindricalunits which are larger in their external diameters than the diameters ofthe apertures of the first disk and are positioned between the firstdisk and the support means so as to be coaxially within the respectivefirst and second apertures, said cylindrical units applying continuousmechanical pressure between the support means and the first disk.
 15. Avalve according to claim 14, including a housing for enclosing the twodisks and the stem but apertured for exposing the upper end of the stemso that it may be manually rotated about a single axis to control thevolume flow rate through the valve.
 16. A valve according to claim 15,including a handle which is affixed to the upper end of the stem to bemanipulated to control the rotary movement of the stem
 17. A faucetvalve for controlling the rate of flow of fluid between a first conduitand a second conduit to be coupled to the valve, comprising first andsecond ceramic disks in contact with each other so as to have a commoninterface, the first disk having two apertures extending through saiddisk and coupled respectively to said first and second conduits, thesecond disk having an elongated unapertured cavity at the commoninterface of sufficient length and depth so as to provide the solecoupling between the two apertures, manually controlled meansperipherally coupled to the second disk for slidably rotating the seconddisk about a single axis always perpendicular to the common interfacefor adjusting the fluid flow rate without rotating the first disk andwithout changing the spacing between the two disks, resilient means forapplying pressure against one of the disks for continuously maintainingthe two disks in physical contact with each other at the interfaceduring all changes in pressure of the incoming fluid and during allrotations of the second disk, said manually controlled means includes asubstantially cylindrical rotary stem mechanically retaining the seconddisk at one end of said stem to control the angular rotation of thesecond disk and also includes a substantially cylindrical collar withinwhich the stem is confined so that the stem is slidably rotatable solelyabout the same axis, a housing enclosing the first and second disks andthe lower segment of the stem, elastomer means inserted within saidapertures of said first disk to apply pressure to the first disk tomaintain it in contact with the second disk at the interface, a cap forsupporting said elastomer means and holding said elastomer means againstthe first disk, and a handle coupled to the upper segment of the stemmanually imparting rotation to the stem, the base of the stem and thesecond disk having projections for limiting the slidable rotation of thesecond disk and the angular rotation of the stem and for Mechanicallycoupling both disks to each other.